Fire alarm signal station



Aug. 17, M, LEVY FIRE ALARM SIGNAL STATION 2 Sheets-Sheet 1 Filed May 13, 1952 INVENTOR.

Patented Aug. 17, 1954 UNITED STATES PATENT OFFICE 2 Claims.

My invention relates to a new and useful fire alarm signal station and, broadly, the object thereof is to produce a signal station including an electric switch normally retained in an open condition and capable of being released by manual action or due to the presence of abnormal heat in the Vicinity of the signal station to cause an alarm to be sounded.

One specific object of the present invention is to produce a fire alarm signal station in which means is provided to normally retain the switch closed, said means being ordinarily maintained in a switch holding position by a fusible element that may be manually disengaged from its anchorage or melted by abnormal heat to release the switch whereby said switch can close to cause a warning signal.

Another object of the invention is to provide a fire alarm signal station including a switch normally maintained in an open position by a frangible panel which may be broken by a spring actuated hammer directly or indirectly held in a neutral or cocked position by a fusible element, said hammer being releasable manually or when the fusible element melts due to the presence of abnormal heat.

Another object of the invention is to provide a spring actuated swinging hammer normally maintained in the neutral position by a fusible link which when manually detached or melted by abnormal heat will release the hammer to break the panel whereby the switch may be closed.

Another object of the invention is to provide a spring actuated hammer projecta-ble in a straight line and controlled by a spring operated bar which, in turn, is maintained in a retracted position by a fusible link that when manually detached or melted by abnormal heat will liberate the bar to release the hammer for breaking the panel to allow the switch to close.

A further object of this invention is to incorporate a fusible element in the frangible panel whereby the switch may be released upon the melting of said fusible element or the breaking of the panel by a separate instrument wielded from the outside of the signal station.

A still further object of the present invention is to provide a fire alarm signal station including a switch normally maintained in an open position by a frangible and fusible panel which when broken or melted will release the switch to permit it to close.

With the above and other objects in view this invention consists of the details of construction and combination of elements hereinafter set forth and then designated by the claims.

In order that those skilled in the art to which this invention appertains may understand how to make and use the same I will describe its construction in detail referring by numerals to the accompanying drawing forming a part hereof, in which:

Fig. l is a perspective view of a fire alarm signal station including a slidably mounted reciprocating bar for controlling the switch, portions being broken away to illustrate details of construction and showing in dotted lines a number of positions the bar may assume for releasing the spring.

Fig. 2 is a section on the line 2-2 of Fig. 1.

Fig. 3 is a perspective View of a signal station having a spring actuated swinging hammer for breaking a frangible panel.

Fig. 4 is a fragmentary perspective view of a modification.

Fig. 5 is a section on the line 5-5 of Fig. 4.

Fig. 6 is a sectional view of another type of alarm station illustrating a fusible element incorporated in the frangible panel.

Fig. 7 is a similar view of a further modification utilizing a frangible and fusible panel show ing it in condition to normally retain the switch in open position.

Fig. 8 is a like view of the same station upon the melting of a portion of the panel.

In carrying out my invention as herein embodied, particular attention being first directed to Figs. 1 and 2, the numeral i0 denotes the body and II is the cover of a casing of a fire alarm signal station, said cover being attached to the body by screws 12 or equivalent fastening means.

The body is to hold an electric switch and for this purpose I have shown a chamber l3 in which is mounted the terminal member [4 and the stationary contact I5 each of which is to be connected with one side of an electric circuit including an alarm device (not shown). Attached to said terminal member is a movable spring contact IS, the free end of which underlies the sta tionary contact reciprocatingly mounted in a recess H in the bottom of the chamber. Said movable contact is fashioned to provide an outwardly projecting knee [8 for a purpose to be presently described.

A switch controlling bar I 9 is slidably mounted longitudinally in a slot 20, Fig. 2, in the casing the movements thereof limited by the length of a slot 2! in the rear end of the bar through which slot is projected a fastener 22 into a suit-able part of the casing, as the body thereof. The bar lies across the open end or top of the chamber in line with the movable contact to engage the knee of said movable contact for depressing the latter to the rear of the aperture 24 is an opening 25- of sufficient size to allow the knee I3 of the movable contact to project therein an appropriate distance to cause said movable contact toengage the stationary contact and close the switch while the bar is depressed but pulledioutwardly longitudinally of itself.

The control bar is held. in a depressed position, as shown by full lines'in Figs. 1 and 2, by a fusible element 26 -of any appropriate construction but which, for purposes of illustration, is shown as comprised of two plates 2i; 28 joined by a solder having a-fairly low melting point. The fusible element 26* has i a slot 29 through which the bar l9 projects for slidably mounting the latter relativeto thefusible element which is normally anchored to the casing by fastening means 3 ii; such as-a= screw.

In a case of fire while-no one is present, the abnormal heat generated will melt the fusible element 2% and liberate the control bar it there by releasing the movable spring contact 45 which issuificiently strong to' lift the bar iii in the casing slot'2li as shown atlfla, to permit said movable contact to engage the stationary contact l and therebyclose the switch in the station for causing an alarm. On the other hand if someone is present and can reach the station before it is'automatically'actuated; the bar 55 can berpulledoutwardly longitudinally of itself; as indicated at i9b. This'will positionthe aperture into alignment'with' the knee iii of the movable spring. contact lfii'atiwhich time said knee may pass through'thezaperture a suihcient distance to cause the movable contact to engage the stationary contact for closingthe switch .to produce an alarm;

In Fig. 3th'e casing'ori body '3l has a chamber fifa' covered by a-i-frangible panel 33 held in place by fastening devices 34-; such as screws. Within chamber 352 ismounteda switch the same as that previously describedvand including the terminal member M" and the stationary contact The movable spring contact leis-attached at one. end to the'terminal member. and has its free and underlying the. stationary contact and reciprocatingly.mountedin the recess fi m the bottom of the chamber 32. Themovable con:- tactit i's-fashioned to provide azknee it which panel 33? engages to depress the movable spring contact l6 and normally holdit out of engagement with its companion stationary contact 15' whereby the switch is. normally open until the panel 33=is broken.

To break the panel 33' a spring operated hammer is provided which includes a head 35 mountedona' shank 3B=having a right angled journal-3'! mounted in bearings 38; Acoil spring 39 surrounds the journal 31- and has: one-end fixed to the body orcasing andthe other end attachedtothe hammer-in a manner'to urge the head towards the panel-33 in the arc of a circle so astostrike-and.breaksaidpanel. The hammer is ordinarily retainedin a-retracted position,.as-.shown:by; full.lines,- by. the fusible element 40 having one end connected to said hammer and the other end termporarily attached to the body or casing by a detachable fastening device M, such as a screw or headed pin.

In operation, when the heat is due to a fire in the vicinity of the station the fusible element 40 will melt and release the hammer which then will be propelled by the spring..39.. until saidehammer hits and breaks: the panel. Thisewill release the movable spring contact of the switch whereby said movable contact will engage the stationary contact to close the switch for causing an alarm. If the fire is not close enough to melt the fusible link and aperson is present the fastening device M can be manually withdrawn and the same purpose accomplished.

The station shown in Figs. 4 and 5 comprises the body or casing 42 having the usual switch holding chamber it across the open end of which isdisposed the frangible panel it} In back of the casing 42 in alignment with the chamber isarecessiti'to provide a partition-"d5 and offset from said" chamber is a' compartment 5? communicating with the I chamber through V a channel @311, 1

In the chamber-43 1s mounted the usual switch including the terminal member 24, the station ary contact l5, themovable spring contact it having one end attached to the terminal -memher and the other or free end underlying the stationary contact and reciprocatinglyreceived in the recess ll; said'movable contact-being pro vided: with an outwardly projecting knee id om actingwith the panel whereby, when the latter isfixed in place; the movable springcontact is depressed to retain the switch in an open condition.

A. longitudinally propelled. hammer t3 is supported; byv the partition t5: underneath of and substantially'at'right angles vto the panel i land is urged towards the same by a spring 29. The hammer is normallyretainediin a retractedposition byacontrolbar 5t which, for purposes of illustration; is shown ashavingxaslot 5i =opening into a hole 52 large enough for thepassage of the hammer. which has a reduced' neck- '53 to be received'inthe-slot 5!; The control bar is urged rearwardlyor retracted byi-a spring. 5c; the tension of whichcanbe adjusted by a screw and said baris moved forwardlyby a. pull rod 55 which is: a'part ofsaid bar although said :parts may actually be separate pieces as shown. The pull rod also has aireduced neck 5? providing acircumferential groovein whichthe fusible element 53 isreceived, the latter. having an. open ended slot 55} whereby said fusible element may be detachably, mounted on the pull redneck.

The operation of the type of station" shown in Figs. 4 and 5 is as follows: When the fusible element 58 is melted by abnormal heat'or: said fusible-element manually removedfrom the pull rod tit-the control rod 38 will be retractedfby' its spring EQ-until the hole. 52in said rod i8: is aligned with the hammer 48 thereby liberating the latter so that itcan be propelled" forwardly by its spring 49; The hammer will break the panel and releasethe movable spring contact; it whereupon it will'engage the stationary contact toclose the switch and produce an alarm... To reset the station, the hammer'is:pushed'iback, the control rod pulled forwardly and the fusible element:replacedroncthe .pull rod, if said fusible element-had been removed intact; or anew-one substituted-if the former one had been melted; Finally. a new panell 44- is. substituted;v forv the broken one and secured in place to depress the movable spring contact and thereby open the switch.

The station shown in Fig. 6 includes a casing 60 having the customary switch holding chamber 6| across the open end of which is disposed the usual frangible panel 62 which, in this instance, has a fusible element 63 in the form of a plug or equivalent structure fixed in a hole 64 in said panel. Within the chamber 6| is mounted the usual switch including the terminal member M, the stationary contact [5, the movable spring contact I6 having one end attached to the terminal member and the other or free end underlying the stationary contact and reciprocatingly with the panel through the medium of the fusible element which it directly engages. The fusible element 63 projects into the switch chamber 6| a sufiicient distance to depress the movable contact out of engagement with the stationary contact to normally maintain the switch in an open condition but when the fusible element is melted there is sufiicient space provided to allow said movable contact to spring outwardly and engage the stationary contact.

In operation, any abnormal heat caused by a fire in the vicinity of the station will melt the fusible element 63 and release the movable contact whereby the switch will be closed and an alarm sounded. To actuate the device manually the panel is broken by a hammer provided for this purpose or any convenient instrument can be used. To reset the device a new panel with the fusible element thereon is put in position to replace the damaged or destroyed one.

The modification illustrated in Figs. '7 and 8 comprises an appropriate casing 65 having the usual switch holding chamber 66 across the open end of which is disposed a frangible and fusible In th chamber 66 is mounted the usual switch including the terminal member M, the stationary contact ill, the movable spring contact 16 having one end attached to the terminal member and the other or free end underlying the stationary contact and reciprocatingly received in the recess [1, said movable spring an outwardly projecting kne I8 coacting with the panel 67.

The movable spring contact pressed by the panel so that the switch is open, as shown in Fig. '7. If the panel is broken by the use of an outside instrument or a fire reaches the station to melt or soften said panel the movable spring contact will deform or push a hole 68, Fig. 8, in said panel to permit said movable,

I6 is normally de- 6 contact to move outwardly a sufiiciefit distance for it in said Fig. 8, whereby an alarm will be sounded.

From the foregoing it will be apparent that I have produced a fire alarm signal station in which the switch is directly controlled by means to be liberated either manually or automatically for releasing said switch to cause the sounding of an alarm.

Of course I do not wish to be limited to the exact details of construction herein shown and described as these may be varied within the scope of the appended claims without departing from the spirit of my invention.

Having described my invention what I claim as new and useful is:

1. A fir alarm signal station comprising a casing body having a chamber open at the front, a cover mounted on said body to close the chamber and provided with a slot in communication with rough an end of the cover to the exterior of the latter, an electric switch located in said chamber and including a movable contact constantly urged towards the open front of the chamber and having a knee projecting outside of th chamber and into the cover slot whereby the switch is closed, a control bar mounted on the body and reciprocal to and fro relative to the chamber and slidable longitudinally within the slot and protruding therefrom said bar coacting with and normally depressing the movable contact to retain the switch in open condition and said ba having a hole through which the knee of the movable contact may pass when said hole is aligned therewith, and a fusible element attached to the casing body and slidably receiving the protruding end of the References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 743,600 Uytenbogaart Nov. 10, 1903 1,095,382 Clorius May 15, 1914 1,106,151 Matthews Aug. 4, 1914 2,570,823 Levy Oct. 9, 1951 

